Over three years after launching in Early Access, Subnautica is finally available in a finished state. But if you haven’t been paying attention over the course of those years, you might be what makes this sandbox survival game different from all the others, and why it’s continuing to burn up the Steam charts even now. In short, it’s a combination of beautiful oceanic sights and deep sea terror that creates experiences all its own, but it doesn’t stop there. Let’s break down what makes Subnautica tick.